Systems and methods for molecular recognition

Abstract

Acoustic wave devices coated with a biolayer are described for the detection target bio-molecules. The acoustic wave device is connected in an oscillator circuit, and the frequency shift Δf resulting from a biomolecular event is recorded. Further described are the use of Rayleigh wave surface acoustic wave devices for vapor phase detection as well as quartz crystal microbalance devices for liquid phase measurements. A biofilm on the surface of the acoustic wave device comprises of a layer of antibodies raised against a specific target molecule or antigen. Signatures for detection events are presented in the form of frequency shifts Δf(t).

1. A method of detecting a biological material in a vaporous sample, the method comprising:
 exposing the vaporous sample to a coated surface of a surface acoustic wave resonator, the coated surface including an immobilized antibody that is antigenic to the biological material, wherein the surface acoustic wave resonator is in communication with an oscillator circuit that monitors in real-time, based on time-dependent perturbation theory, a surface acoustic waveform produced by the surface acoustic wave resonator; 
 after exposing the biological material to the coated surface, detecting presence of the biological material in the vaporous sample, detecting the presence of the biological material further including detecting, using the oscillator circuit, a change in a signature of the surface acoustic waveform of the coated material, and comparing this signature-change in the surface acoustic waveform to a reference signature-change indicative of the presence of the biological material. 
 
     
     
       2. The method of  claim 1 , wherein the immobilized antibody is a monoclonal antibody. 
     
     
       3. The method of  claim 2 , wherein the monoclonal antibody is an IgG monoclonal antibody. 
     
     
       4. The method of  claim 1 , wherein the reference signature-change is selected from a database including a plurality of reference signature-changes indicative of the presence of a plurality of biological materials. 
     
     
       5. The method of  claim 1 , wherein the biological material includes a form of cocaine. 
     
     
       6. The method of  claim 5 , wherein the immobilized antibody includes an antibody for benzoylecgonine. 
     
     
       7. The method of  claim 1 , wherein the signature-change in the surface acoustic waveform includes a change in a frequency of the surface acoustic waveform. 
     
     
       8. The method of  claim 7 , further including:
 prior to comparing the signature-change in the surface acoustic waveform, subtracting a baseline waveform from the surface acoustic waveform after the exposure of the biological material, wherein the baseline waveform is characteristic of the coated surface when unbound from the biological material.